This specification relates to digital data processing and, in particular, document collection navigation.
An electronic document is a collection of machine-readable data. Electronic documents are generally individual files and are formatted in accordance with a defined format (e.g., PDF, TIFF, HTML, MS Word, PCL, PostScript, or the like). Electronic documents can be electronically stored and disseminated. In some cases, electronic documents include audio content, visual content, and other information, as well as text and links to other electronic documents. A document may be stored in a portion of a file that holds other documents, in a single file dedicated to the document in question, or in multiple coordinated files.